Lochinvar CF-CH(E)-i&s-08, 399 Gas Manifold Pressure Adjustment, Installation and Service Manual

Installation and Service Manual

Check burner performance by cycling the system while you observe burner response. Burners should ignite promptly. Flame pattern should be stable, see Burner Flames, page 56. Turn system off and allow burners to cool, then cycle burners again to ensure proper ignition and flame characteristics.

Gas Manifold Pressure Adjustment

IMPORTANT: The gas valves are referenced to the fan pressurized chamber by a hose connected from the vent of the gas valve regulator to the chamber pressure tap located on the front inside portion of the jacket. Reference the drawings in this section for component and connection points for pressure measurement. The procedure for connecting a manometer or magnehelic must be followed to obtain actual net manifold pressure for normal operation. A manometer or magnehelic gauge legible in 0.1" increments up to 10 inches w.c. is required to check and adjust the manifold pressure. The regulator cover screw on the gas valve must be in place and tight at all times for the unit to operate properly.

1.Loosen knurled knob that fastens the control panel access door and pull out control panel.

2.Turn the power switch located in the lower left corner behind the control panel access door to the “O” or “OFF” position.

3.Remove the top front jacket access panels to access the gas valves.

FIG. 30 Measuring Gas Supply Pressure at Combination

Gas Valve

TABLE - L

Multiple Unit Installations Gas Supply Pipe Sizing

Nominal Iron				Length of Pipe In Straight Feet
Pipe Size,
(Inches)	10	20	30	40	50	60	70	80	90	100	125	150	175	200
3/4"	369	256	205	174	155	141	128	121	113	106	95	86	79	74
1"	697	477	384	328	292	267	246	256	210	200	179	164	149	138
1 1/4"	1,400	974	789	677	595	543	502	472	441	410	369	333	308	287
1 1/2"	2,150	1,500	1,210	1,020	923	830	769	707	666	636	564	513	472	441
2"	4,100	2,820	2,260	1,950	1,720	1,560	1,440	1,330	1,250	1,180	1,100	974	871	820
2-1/2"	6,460	4,460	3,610	3,100	2,720	2,460	2,310	2,100	2,000	1,900	1,700	1,540	1,400	1,300
3"	11,200	7,900	6,400	5,400	4,870	4,410	4,000	3,800	3,540	3,300	3,000	2,720	2,500	2,340
4"	23,500	16,100	13,100	11,100	10,000	9,000	8,300	7,690	7,380	6,870	6,150	5,640	5,130	4,720

Maximum capacity of pipe in thousands of BTU’s per hour for gas pressures of 14 Inches Water Column (0.5 PSIG) or less and a total system pressure drop of 0.5 Inch Water Column (Based on NAT GAS, 1025 BTU’s per Cubic Foot of Gas and 0.60 Specific Gravity).

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